A well system (e.g., oil or gas wells for extracting fluids from a subterranean formation) can include a wellbore drilled into a formation. A casing string can be positioned in the wellbore to prevent walls of the wellbore from caving in. Cement can be pumped into a space between the casing string and the walls of the wellbore (or the walls of another casing string). The cement can bond the casing string to the walls of the wellbore (or the other casing string).
The properties of the cement can change as the cement sets. For example, the physical state of the cement can change from a fluid state to a solid state. It can be challenging to detect and communicate information about the fluid to the well surface efficiently.